Electrochromic devices have received great attention due to the steep growth of smart window markets and demands from various emerging fields. Recently, elaborately designed materials not only enhanced coloring/bleaching performances but also provided additional functionality, energy storage, since electrochromism relies on capture and release of ions. Meanwhile, given that electrochromic devices are mostly targeted for large-scale applications such as smart windows, there are still significant needs for further advances, especially in terms of reliability and simplicity of materials and their manufacturing processes. In this study, double-layer hydroxide films are reported as energy-storable electrochromic materials with ultrafast transition kinetics. Core/shell-like Co(OH)₂/Ni(OH)₂ films produced within a minute of electrodepositions have capabilities for multiple color changes and show extremely fast optical responses that are comparable to state-of-the-arts. In addition, the electrodeposited hydroxide films manifest high capacitance and rate capabilities when applied as capacitors, with electrochromic kinetics an order of magnitude higher than those with similar level of capacities for energy storage.

由于智能窗市场的急剧增长以及各个新兴领域的需求，电致变色设备受到了极大的关注。最近，由于电致变色依赖于离子的捕获和释放，精心设计的材料不仅增强了着色/漂白性能，而且还提供了附加功能和能量存储。同时，鉴于电致变色设备主要针对诸如智能窗之类的大规模应用，因此仍然存在对进一步发展的重大需求，特别是在材料及其制造工艺的可靠性和简单性方面。在这项研究中，双层氢氧化物膜被报道为具有超快跃迁动力学的可储能电致变色材料。核/壳状Co（OH）₂ / Ni（OH）₂在一分钟的电沉积过程中生产的薄膜具有多种颜色变化的能力，并且显示出与最新技术相当的极快的光学响应。另外，电沉积的氢氧化物膜当用作电容器时表现出高的电容和倍率能力，其电致变色动力学比具有类似水平的储能能力的电致变色动力学高一个数量级。